Association Between Self-Monitored Blood Glucose and Continuous Glucose Monitoring in Youth With Type 1 Diabetes and Medicaid Insurance

Youth with type 1 diabetes (T1D) and Medicaid must demonstrate they have self-monitored their blood glucose level at least four times daily to receive continuous glucose monitors (CGMs). New California Medicaid policies eliminated this requirement and, thus, CGM access has increased. This study examines whether infrequent baseline self-monitored blood glucose (SMBG) checks result in suboptimal outcomes or nonadherence with CGM use.

This retrospective study included youth with T1D and Medicaid who started CGM after January 2019, when newer models no longer needed calibration, at two large health care systems. Patients were stratified by data on baseline SMBG frequency (<4 vs. ≥4 checks daily) collected at the clinic visit prior to starting CGM. Differences between SMBG groups in CGM adherence and HbA_1c over time were assessed by a mixed-effects linear regression model and fixed-effect interaction term. Patients were surveyed to explore individual impact of CGM on diabetes management.

We followed 78 youth for 6 months. CGM adherence was similar between SMBG frequency groups at 3 months (68.7% vs. 68.4%; P = 0.97) and sustained at 6 months. HbA_1c values improved in both groups at 3 months, with a larger improvement in those with SMBG <4 daily checks (1.3% vs. 0.4%), and sustained at 6 months. Patient surveys (n = 35) reported high engagement with CGM and increased insulin boluses after initiation.

Patients using CGM demonstrated improvement in HbA_1c regardless of prior SMBG. Increased engagement with CGM likely promoted increased insulin boluses. Therefore, restriction of CGM to those with SMBG ≥4 daily checks is an unnecessary barrier, excluding those who could potentially benefit the most.